Increase Clarity of WMS

[Jared Chapiewsky]

I had problems with chunky Raster WMSs too, specifically with 
TerraServer orthophotos. My solution was to change the format for the 
layer to jpeg, like so:

 "WMS_FORMAT" "image/jpeg"

and I added one line to my outputformat block for jpeg in the mapfile, 
like this:

FORMATOPTION "QUALITY=100"

I'm still serving the final output as png, and there is no chunkiness at 
all. I didn't have to mess with any of the PROCESSING options either.

Cheers,

Jared Chapiewsky



Gary Watry wrote:

>My website is 
>
>http://gw102.coaps.fsu.edu/httpdocs/indexmaster.html
>
>The layer code for a wms file is 
>
>LAYER
>  NAME Blue_Marble
>   STATUS OFF
>   TYPE RASTER
>   OFFSITE 0 0 0
>   GROUP "Background"
>   CONNECTIONTYPE WMS
>   CONNECTION "http://wms.jpl.nasa.gov/wms.cgi?"
>   PROJECTION
>     "init=epsg:4326"
>   END
>  METADATA
>     "wms_name" "modis"
>     "wms_server_version" "1.1.1"
>     "wms_srs" "EPSG:4326"
>     "wms_format" "image/png"
> END
>END
>
>
>If you look at it the file is real chunky or blocky, all the wms files work
>the same.
>
>Any suggestions?
>______________________________________________________________
>Gary L. Watry
>
>GIS Coordinator
>Center for Ocean-Atmospheric Prediction Studies
>FSU / COAPS
>Johnson Building, RM 215
>2035 East Paul Dirac Drive
>Tallahassee, Florida 32306-2840
> 
>E-Mail: watry at coaps.fsu.edu
>
>
>-----Original Message-----
>From: UMN MapServer Users List [mailto:MAPSERVER-USERS at lists.umn.edu] On
>Behalf Of Clint Johnson
>Sent: Friday, April 07, 2006 7:34 PM
>To: MAPSERVER-USERS at lists.umn.edu
>Subject: Re: [UMN_MAPSERVER-USERS] Increase Clarity of WMS
>
>Kyle,
>
>Your error is due to the line that says
>  PROCESSING "RESAMPLE=AVERAGE"
>
>If you want a quality image then by all means do NOT use average dithering.
>example of average dithering 
>http://www.visgraf.impa.br/Courses/ip00/proj/Dithering1/average_dithering.ht
>ml
>
>Use one of:
>
>PROCESSING "RESAMPLE=BILINEAR"
>PROCESSING "RESAMPLE=BICUBIC" # preferable
>
>
>Stay away from nearest and average.
>
>Without having to go into Digital processing 101, using nearest or 
>average will cause your image to "chunk" when it is re-sampled (ie 
>zoomed in or out); whereas, bilinear and bicublic will give it a nice 
>"anti-aliased" look as you zoom in.
>
>Cheers,
>Clint
>
>
>  
>